Method for making carbon nanotube film

ABSTRACT

A method for making carbon nanotube film includes providing a first patterned carbon nanotube array and a second patterned carbon nanotube array having a predetermined pattern, wherein the predetermined pattern is a parallelogram. An acute angle of the parallelogram in the second patterned carbon nanotube arrays is adjacent to an obtuse angle of the parallelogram in the first patterned carbon nanotube array. A carbon nanotube film is pulled out from an acute angle vertex of the first patterned carbon nanotube array. A carbon nanotube film preform is pulled out from an acute angle vertex of the second patterned carbon nanotube array and the carbon nanotube film preform is connected to an obtuse angle vertex of the first patterned carbon nanotube array. And then, the carbon nanotube film continues to be pulled.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims all benefits accruing under 35 U.S.C. §119 fromChina Patent Application No. 201410269129.2, filed on Jun. 17, 2014, inthe China Intellectual Property Office. This application is related tocommonly-assigned application entitled, “METHOD FOR MAKING CARBONNANOTUBE FILM”, concurrently filed (Atty. Docket No.US52953).Disclosures of the above-identified applications are incorporated hereinby reference.

FIELD

The present application relates to a method for making carbon nanotubefilm.

BACKGROUND

Carbon nanotubes are tubules of carbon generally having a length of 5 to100 micrometers and a diameter of 0.5 to 100 nanometers. Carbonnanotubes can be composed of a number of coaxial cylinders of graphitesheets, and have recently attracted a great deal of attention for use indifferent applications such as field emitters, gas storage andseparation, chemical sensors, and high strength composites. Recently,carbon nanotube films have been fabricated. A carbon nanotube filmincludes a plurality of carbon nanotube bundles that are joined end toend by van der Waals attractive force. Each of the carbon nanotubebundles includes a plurality of carbon nanotubes substantially parallelto each other. The plurality of carbon nanotube bundles joined end toend by van der Waals attractive force form the continuous carbonnanotube film. After being treated with organic solvent, the carbonnanotube film can be readily used in cables, printed circuit boards,cloths, and other macroscopic applications.

For mass production, the carbon nanotube film should be relatively long.However, the length of the carbon nanotube film is limited by an area ofa super-aligned carbon nanotube array from which the carbon nanotubefilm is derived. In general, a diagonal length of a rectangularsuper-aligned carbon nanotube array is only about 4 inches. Thus, thelength of the carbon nanotube film is correspondingly limited.

What is needed, therefore, is to provide a method for making carbonnanotube film that can overcome the above-described shortcomings.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by wayof example only, with reference to the attached figures, wherein:

FIG. 1 is a schematic process flow of one embodiment of a method formaking a carbon nanotube film.

FIG. 2 is a schematic view of one embodiment of a carbon nanotube array.

FIG. 3 is a schematic view of one embodiment of a patterned carbonnanotube array.

FIG. 4 is a schematic view of one embodiment of another patterned carbonnanotube array.

FIG. 5 is a schematic view of one embodiment of yet another patternedcarbon nanotube array.

FIG. 6 is a schematic view of one embodiment of yet another patternedcarbon nanotube array.

FIG. 7 is a schematic view of one embodiment of a second carbon nanotubefilm preform without connecting to a first patterned carbon nanotubearray.

FIG. 8 is a schematic view of one embodiment of treating the carbonnanotube film of FIG. 1 with organic solvent.

FIG. 9 is a schematic view of one embodiment of twisting the carbonnanotube film of FIG. 1.

FIG. 10 is a schematic view of another embodiment of a first carbonnanotube structure preform.

FIG. 11 is a schematic view of another embodiment of a patterned carbonnanotube array.

FIG. 12 is a schematic view of yet another embodiment of a second carbonnanotube structure preform.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures and components have notbeen described in detail so as not to obscure the related relevantfeature being described. The drawings are not necessarily to scale andthe proportions of certain parts may be exaggerated to better illustratedetails and features. The description is not to be considered aslimiting the scope of the embodiments described herein.

Several definitions that apply throughout this disclosure will now bepresented.

The term “coupled” is defined as connected, whether directly orindirectly through intervening components, and is not necessarilylimited to physical connections. The connection can be such that theobjects are permanently connected or releasably connected. The term“outside” refers to a region that is beyond the outermost confines of aphysical object. The term “inside” indicates that at least a portion ofa region is partially contained within a boundary formed by the object.The term “substantially” is defined to be essentially conforming to theparticular dimension, shape or other word that substantially modifies,such that the component need not be exact. For example, substantiallycylindrical means that the object resembles a cylinder, but can have oneor more deviations from a true cylinder. The term “comprising” means“including, but not necessarily limited to”; it specifically indicatesopen-ended inclusion or membership in a so-described combination, group,series and the like.

The disclosure is illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that referencesto “an” or “one” embodiment in this disclosure are not necessarily tothe same embodiment, and such references mean at least one.

Referring to FIGS. 1-3, an embodiment of a method for making a carbonnanotube film 100 of one embodiment includes following steps:

S10, providing a plurality of carbon nanotube arrays 14 spaced from eachother and arranged along a horizontal direction, wherein the horizontaldirection is defined as X direction, and the plurality of carbonnanotube arrays 14 is located in a same plane;

S20, patterning the plurality of carbon nanotube arrays 14 to form aplurality of patterned carbon nanotube arrays successively defined as afirst patterned carbon nanotube array 10, a second patterned carbonnanotube array 20, . . . , and the N-th patterned carbon nanotube array40, the letter N represent the number of the plurality of patternedcarbon nanotube arrays, N≧2, wherein each of the plurality of patternedcarbon nanotube arrays includes a first end 102 and a second end 104opposite to the first end 102, and the first end 102 of each of theplurality of patterned carbon nanotube arrays is close to the second end104 of the adjacent patterned carbon nanotube array; S30, pulling out asecond carbon nanotube film preform 22 from the first end 102 of thesecond patterned carbon nanotube array 20, and connecting the secondcarbon nanotube film preform 22 to the second end 104 of the firstpatterned carbon nanotube array 10;

S40, pulling out a third carbon nanotube film preform 32 from the firstend 102 of the third patterned carbon nanotube array 30, and connectingthe third carbon nanotube film preform 32 to the second end 104 of thesecond patterned carbon nanotube array 20;

S50, pulling out a plurality of carbon nanotube film preforms from thesecond patterned carbon nanotube array 20 to the N-th patterned carbonnanotube array 40 and connecting the plurality of carbon nanotube filmpreforms to adjacent patterned carbon nanotube arrays by repeating steps(S30) and (S40) as often as desired; and

S60, pulling out a carbon nanotube film 100 from the first end 102 ofthe first pattern carbon nanotube array 10, wherein the pullingdirection is along the X direction.

In the step (S10), the plurality of carbon nanotube arrays 14 is spacedfrom each other and located in the same plane. The carbon nanotube array14 is fabricated by a chemical vapor deposition process in oneembodiment. The chemical vapor deposition process includes the substepsof:

(S101), providing a substantially flat and smooth substrate 12, whereinthe substrate 12 can be a P-type silicon substrate, an N-type siliconsubstrate, or a silicon substrate having oxide layer disposed thereon.In one embodiment, the substrate 12 is a P-type silicon substrate havinga width of about 4 inches;

(S102), forming a catalyst on the surface of the substrate 12, whereinthe catalyst can be made of iron, cobalt, nickel, or any combinationalloy thereof;

(S103), annealing the substrate 12 with the catalyst at a temperatureranging from about 700° C. to about 900° C. in air for about 30 minutesto about 90 minutes;

(S104), heating the substrate 12 with the catalyst at a temperatureranging from about 500° C. to about 740° C. in a furnace with aprotective gas therein; and

(S105), supplying a carbon source gas to the furnace for about 5 minutesto about 30 minutes and growing the carbon nanotube array 14 on thesubstrate 12, wherein the carbon source gas may be hydrocarbon gas, suchas ethylene, methane, acetylene, ethane, or any combination thereof.

Each of the plurality of carbon nanotube arrays 14 includes a pluralityof carbon nanotubes parallel to each other. The plurality of carbonnanotubes is substantially perpendicular to a surface of the substrate12. Moreover, the plurality of carbon nanotube arrays 14 formed underthe above conditions is essentially free of impurities such ascarbonaceous or residual catalyst particles.

In the step (S20), referring to FIG. 3, each of the plurality ofpatterned carbon nanotube arrays includes a plurality of carbonnanotubes parallel to each other and perpendicular to the surface of thesubstrate 12. The plurality of carbon nanotubes in each of the pluralityof patterned carbon nanotube arrays is arranged and formed apredetermined pattern. Each carbon nanotube includes a top end and abottom end opposite to the top end, wherein the bottom end of eachcarbon nanotube is in contact with the surface of the substrate 12, andthe top end is away form the surface of the substrate 12. The top endsof the plurality of carbon nanotubes form the predetermined pattern.

The predetermined pattern includes a rectangle 106, a first triangle108, and a second triangle 110. The first triangle 108 and the secondtriangle 110 are respectively located on two opposite sides of therectangle 106. The first triangle 108 and the rectangle 106 share oneside, the second triangle 110 and the rectangle 106 share one side. Indetail, the rectangle 106 includes a first side 1060 and a second side1062 opposite to the first side 1060. The first side 1060 and the secondside 1062 of the rectangle 106 are perpendicular to X direction. In eachpatterned carbon nanotube array, the first end 102 is a vertex of thefirst triangle 108. A third side 1080, a fourth side 1082, and the firstside 1060 of the rectangle 106 form the first triangle 108. The firstend 102 is a crossover point of the third side 1080 and the fourth side1082. The second end 104 is a vertex of the second triangle 110. A fifthside 1100, a sixth side 1102, and the second side 1062 of the rectangle106 form the second triangle 110. The second end 104 is a crossoverpoint of the fifth side 1100 and the sixth side 1102. In one embodiment,the plurality of patterned carbon nanotube arrays has the samestructures, dimensions, and predetermined patterns.

A distance between the first end 102 and the first side 1060 is equal toa distance between the second end 104 and the second side 1062. In oneembodiment, the first triangle 108 and the second triangle 110 have thesame dimension. The first side 1060 is designed as a base side of thefirst triangle 108, and the second side 1062 is designed as a base sideof the second triangle 110. A height of the first triangle 108 in the Xdirection is equal to a height of the second triangle 110 in the Xdirection.

The first triangle 108 and the second triangle 110 can be formed aparallelogram. The first triangle 108 and the second triangle 110 can besimultaneously an acute triangle, an obtuse angled triangle, or a righttriangle.

Referring to FIG. 3, both the first triangle 108 and the second triangle110 are acute triangles. The third side 1080 of the first triangle 108is parallel to the sixth side 1102 of the second triangle 110. Thefourth side 1082 of the first triangle 108 is parallel to the fifth side1100 of the second triangle 110. In one embodiment, both the firsttriangle 108 and the second triangle 110 are isosceles triangles. In oneembodiment, both the first triangle 108 and the second triangle 110 areequilateral triangles.

Referring to FIG. 4, both the first triangle 108 and the second triangle110 are obtuse angled triangles. The third side 1080 of the firsttriangle 108 is parallel to the sixth side 1102 of the second triangle110. The fourth side 1082 of the first triangle 108 is parallel to thefifth side 1100 of the second triangle 110. In the first triangle 108,the third side 1080 and the fourth side 1082 form an obtuse angle; andin the second triangle 110, the fifth side 1100 and the sixth side 1102form an obtuse angle.

Referring to FIGS. 5 and 6, both the first triangle 108 and the secondtriangle 110 are right triangles. In FIG. 5, the first side 1060 of therectangle 106 is the hypotenuse of the first triangle 108, and thesecond side 1062 of the rectangle 106 is the hypotenuse of the secondtriangle 110. In one embodiment, the first triangle 108 and the secondtriangle 110 are isosceles tight triangles. In FIG. 6, the first side1060 of the rectangle 106 is a leg of the first triangle 108, the secondside 1062 of the rectangle 106 is a leg of the second triangle 110, anda line between the first end 102 and a second end 104 is parallel to theX direction.

Methods for patterning the plurality of carbon nanotube arrays 14 can beselected according to need. In one embodiment, the plurality of carbonnanotube arrays 14 are patterned by irradiating the plurality of carbonnanotube arrays 14 with a laser beam.

The laser beam irradiates the plurality of carbon nanotube arrays 14along a predetermined path on the plurality of carbon nanotube arrays 14thereby to cut predetermined pattern within the path in each of theplurality of carbon nanotube arrays 14. The laser beam has a power ofabout 3.6 to about 12 watts and a moving speed of about 1 to about 1000mm/s. The laser beam can be a YAG laser. The laser beam has a wavelengthof 1.06 microns and a beam spot diameter of 20 microns. In oneembodiment, the moving speed of the laser beam is in a range from about10 mm/s to about 90 mm/s. The laser beam will not damage the substrate12.

It is to be understood, patterning the plurality of carbon nanotubearrays 14 with the laser beam can also be carried out by fixing thelaser beam and moving the plurality of carbon nanotube arrays 14 by acomputer program along the predetermined portion.

In the step (S30), the second carbon nanotube film preform 22 can bepulled/drawn by the following substeps:

(S31), selecting multiple carbon nanotubes of the second patternedcarbon nanotube array 20 by using a tool 50; and

(S32), pulling the carbon nanotubes at an even/uniform speed to secondcarbon nanotube film preform 22.

In the step (S31), the tool 50 can be an adhesive tape, plier, tweezer,or another tool allowing multiple carbon nanotubes to be gripped andpulled simultaneously.

In the step (S32), a pulling direction is arbitrary. In one embodiment,the pulling direction is substantially perpendicular to a growingdirection of plurality of carbon nanotube arrays 14.

During the pulling process, as the initial carbon nanotubes are drawnout, other carbon nanotubes are also drawn out end-to-end due to the vander Waals attractive force between ends of adjacent carbon nanotube.This process of drawing ensures that a continuous, uniform second carbonnanotube film preform 22 having a predetermined width can be formed.

The second carbon nanotube film preform 22 is a substantially purestructure of the carbon nanotubes, with few impurities. The carbonnanotubes of the second carbon nanotube film preform 22 have lowspecific surface area, and are combined by van der Waals attractiveforce. Thus, the second carbon nanotube film preform 22 has viscosityand can be directly connected to the second end 104 of the firstpatterned carbon nanotube array 10 without an adhesive. It is to beunderstood that the second carbon nanotube film preform 22 can beconnected to the second end 104 of the first patterned carbon nanotubearray 10 by an adhesive.

The second carbon nanotube film preform 22 can be connected to thesecond side 1062 of the rectangle 106 of the first patterned carbonnanotube array 10. In one embodiment, the second carbon nanotube filmpreform 22 is connected to middle point of the second side 1062 of therectangle 106 of the first patterned carbon nanotube array 10. Indetail, the second carbon nanotube film preform 22 has a first end point222 and a second end point 224 opposite to the first end point 222. Thefirst end point 222 is connected to the first end 102 of the secondpatterned carbon nanotube array 20. The second end point 224 isconnected to the second side 1062 of the rectangle 106 of the firstpatterned carbon nanotube array 10.

The steps (S40), (S50) and (S30) have the same process.

In the step (S60), the tool 50 selects some carbon nanotubes of thefirst patterned carbon nanotube array 10 having a determined width, andthen pulled away from the first patterned carbon nanotube array 10 at aneven/uniform speed to make the carbon nanotubes separate from the firstpatterned carbon nanotube array 10. The pulling direction can besubstantially perpendicular to the growing direction of the plurality ofcarbon nanotube arrays 14.

During the extracting process, when the carbon nanotubes of the secondside 1062 of the rectangle 106 or second end 104 of the first patternedcarbon nanotube array 10 is pulled, the carbon nanotubes of the secondpatterned carbon nanotube array 20 begin to pull away from the secondpatterned carbon nanotube array 20, because the second carbon nanotubefilm preform 22 connects to the carbon nanotubes of the second side 1062of the rectangle 106 or second end 104 of the first patterned carbonnanotube array 10. In this way, until the carbon nanotubes of the N-thpatterned carbon nanotube array 40 are pulled.

During the extracting process, when ends of the carbon nanotubes of thefirst patterned carbon nanotube array 10 is drawn out, other carbonnanotubes are also drawn out in a manner that ends of a carbon nanotubeis connected with ends of adjacent carbon nanotubes, by the help of thevan der Waals attractive force between the ends of carbon nanotubes.This characteristic of the carbon nanotubes ensures that a continuouscarbon nanotube film 100 having a width can be formed.

The carbon nanotube film 100 can comprise or consist of a plurality ofcarbon nanotubes extending along a same direction. The plurality ofcarbon nanotubes is parallel to a surface of the carbon nanotube film100 and extends along the pulling direction. Along the extendingdirection of the plurality of carbon nanotubes, each carbon nanotube isjoined to adjacent carbon nanotubes end to end by van der Waalsattractive force therebetween, whereby the carbon nanotube film 100 iscapable of being free-standing structure.

In the process of forming the carbon nanotube film 100, the number ofthe carbon nanotubes of the carbon nanotube film 100 remains unchanged.In the carbon nanotube film 100, the number of the carbon nanotubes ineach cross section of the carbon nanotube film 100 perpendicular to thepulling direction remains unchanged. Specific analysis is as follows.

FIG. 7 is a schematic view of one embodiment of the second carbonnanotube film preform 22 without connecting to the first patternedcarbon nanotube array 10. The width of the second carbon nanotube filmpreform 22 or the width of the carbon nanotube film 100 is related tothe area of the plurality of patterned carbon nanotube arrays. Thenumber of the carbon nanotubes, in the second carbon nanotube filmpreform 22 or the carbon nanotube film 100, is related to the area ofthe plurality of patterned carbon nanotube arrays. In the process ofpulling the carbon nanotubes, the pulling speed is even/uniform. Whenthe carbon nanotubes of the second side 1062 of the rectangle 106continue being pulled, the number of the carbon nanotubes of the carbonnanotube film 100 will reduce because the area of first patterned carbonnanotube array 10 reduces. During the time from 0 to T, the carbonnanotubes of the second side 1062 of the rectangle 106 are pulled untilthe carbon nanotubes of the line CD of the first patterned carbonnanotube array 10. During the time from 0 to T, the area of the firstpatterned carbon nanotube array 10 reduced is equal to total area oftriangle IAC and triangle BGD. And during the time from 0 to T, thecarbon nanotubes of the first end 102 of the second patterned carbonnanotube array 20 are pulled until the carbon nanotubes of the line FGof the second patterned carbon nanotube array 20 are pulled.

In each patterned carbon nanotube array, the first triangle 108 and thesecond triangle 110 can form a parallelogram, thus ∠E of triangle EFG=∠Aof triangle IAC+∠B of triangle BGD. In the condition of even/uniformspeed, the area of the triangle EFG is equal to total areas of thetriangle IAC and the triangle BGD.

Therefore, when the second carbon nanotube film preform 22 connects tothe carbon nanotubes of the second side 1062 of the rectangle 106 of thefirst patterned carbon nanotube array 10, the reduced carbon nanotubesof the carbon nanotube film 100 can be compensated. The rest may bededuced by above analogy, when each carbon nanotube film preform pulledfrom each patterned carbon nanotube array connects to the second side1062 of the rectangle 106 of previous patterned carbon nanotube array,the number of the carbon nanotubes of the carbon nanotube film 100remains unchanged in whole extracting process.

The method for making the carbon nanotube film 100 further includestreating the carbon nanotube film 100 to a carbon nanotube wire 200.

The carbon nanotube film 100 can be treated by an organic solvent 70 toform the carbon nanotube wire 200. The carbon nanotube wire 200 is anuntwisted carbon nanotube wire 200. A method for treating carbonnanotube film 100 with the organic solvent 70 can be selected accordingto need. In one embodiment, referring to FIG. 8, a first container 60located on upside of the carbon nanotube film 100 contains the organicsolvent 70 for shrinking the carbon nanotube film 100. The organicsolvent 70 can be ethanol, methanol, acetone, dichloroethane,chloroform, or the combinations thereof. In one embodiment, the organicsolvent 70 is ethanol. The first container 60 includes a tube 62 on itssidewall. The tube 62 has a through hole 64 defined therein for allowingthe carbon nanotube film 100 pass therethrough. The first container 60is configured for supplying the organic solvent 70 to the tube 62. Asecond container 80 is placed below the through hole 64 of the tube 62for collecting leaking organic solvent 70.

The carbon nanotube film 100 is passed through the through hole 64 ofthe tube 62 continuously and soaked in the organic solvent 70. Thus thecarbon nanotube film 100 is shrunk into the carbon nanotube wire 200with a diameter of 20-30 microns under the action of surface tension ofthe organic solvent 70.

The carbon nanotube wire 200 includes a plurality of carbon nanotubespacked closely together. The plurality of carbon nanotubes extends alongan axial of the carbon nanotube wire 200. In the extending direction ofcarbon nanotubes, the plurality of carbon nanotubes are joined end toend by van der Waals attractive force. The ratio of surface area tovolume of the carbon nanotube wire 200 is low and the carbon nanotubewire 200 thus has non-stick properties.

Referring to FIG. 9, the carbon nanotube film 100 can be twisted intothe carbon nanotube wire 200 that is a twisted carbon nanotube wire 200.In the process of twisting carbon nanotube film 100, carbon nanotubefilm 100 is still being drawn and joined with the carbon nanotube array14. In the length direction, one end of the carbon nanotube film 100 isconnected with the carbon nanotube array 14 by van der Waals attractiveforce, other end is held by the tool 50. The substrate 12 can be fixed,while the tool 50 is rotated, the carbon nanotube film 100 is twistedinto the carbon nanotube wire 200. The rotation direction issubstantially perpendicular to the length direction of the carbonnanotube film 100. The tool 50 can be fixed on a rotating machine topull and rotate simultaneously.

While rotating the tool 50, a pulling force is still applied on thecarbon nanotube film 100, and the plurality of carbon nanotube istwisted. Further, by pulling the tool 50, more and more carbon nanotubescan be drawn from the patterned carbon nanotube array to extend thelength of the carbon nanotube film 100. In one embodiment, the value oftwist force is in a range from about 0.00005 Newton to about 0.001Newton.

The carbon nanotube wire 200 formed by twisting the carbon nanotube film100 includes a plurality of carbon nanotubes helically oriented aroundan axial direction of the carbon nanotube wire 200. Therefore, thecarbon nanotube wire 200 formed by twisting the carbon nanotube film 100has a larger mechanical strength.

The carbon nanotube wire 200 can be coiled onto a bobbin 92 with anelectromotor 90 or by hand.

The number of carbon nanotubes of the carbon nanotube film 100 remainsunchanged in pulling out the carbon nanotube film 100. When the carbonnanotube film 100 is treated into the carbon nanotube wire 200, thenumber of the carbon nanotubes of the carbon nanotube wire 200 isuniform. The carbon nanotube wire 200 has uniform quantity of carbonnanotubes. Thus, the carbon nanotube wire 200 has a uniform diameter,improving mechanical properties of the carbon nanotube wire 200.

An embodiment of the method for making the carbon nanotube film 100 isshown where the carbon nanotube film 100 is pulling out from a firstcarbon nanotube structure preform 300.

Referring to FIG. 10, the first carbon nanotube structure preform 300includes N patterned carbon nanotube arrays and N−1 carbon nanotube filmpreforms. The N patterned carbon nanotube arrays are spaced from eachother and arranged along the X direction, N≧2. Each patterned carbonnanotube array includes the substrate 12 and a plurality of carbonnanotubes substantially parallel to each other and substantiallyperpendicular to the surface of the substrate 12. The plurality ofcarbon nanotubes forms the predetermined pattern. The predeterminedpattern includes the rectangle 106, the first triangle 108, and thesecond triangle 110. The first triangle 108 and the second triangle 110are respectively located on two opposite sides of the rectangle 106. Therectangle 106 includes a first side 1060 and a second side 1062 oppositeto the first side 1060. A base side of the first triangle 108 and therectangle 106 share the first side 1060, a base of the second triangle110 and the rectangle 106 share the second side 1062. The first side1060 and the second side 1062 of the rectangle 106 are perpendicular tothe X direction. The height of the first triangle 108 in the X directionis equal to the height of the second triangle 110 in the X direction.

Each carbon nanotube film preform is located between two adjacentpatterned carbon nanotube arrays and pulled out from a vertex angle ofthe first triangle 108 of N−1-th patterned carbon nanotube arrays. Eachcarbon nanotube film preform includes the first end point 222 and thesecond end point 224 opposite to the first end point 222. The first endpoint 222 is connected to the base side of the second triangle 110 ofthe N-th patterned carbon nanotube array. The second end point 224 isconnected to the vertex angle of the first triangle 108 of N−1-thpatterned carbon nanotube arrays. The vertex angle of the first triangle108 is equal to the vertex angle of second triangle 110. The vertexangle of the first triangle 108 is opposite to the base side of thefirst triangle 108. The vertex angle of the second triangle 110 isopposite to the base side of the second triangle 110. When both thefirst triangle 108 and the second triangle 110 are obtuse angledtriangles, the vertex angle of the first triangle 108 and the vertexangle of the second triangle 110 are greater than 90 degrees.

The N−1 carbon nanotube film preforms are suspended. The N−1 carbonnanotube film preforms include the plurality of carbon nanotubes joinedend to end by van der Waals attractive force and extending along the Xdirection.

Referring to FIG. 11, an embodiment of the method for making the carbonnanotube film 100 is shown where the predetermined pattern is aparallelogram including the first triangle 108, the second triangle 110,and the rectangle 106, wherein the first triangle 108 and the secondtriangle 110 are right triangles. The first side 1060 of the rectangle106 is a leg of the first triangle 108, the second side 1062 of therectangle 106 is a leg of the second triangle 110. The parallelogramincludes the first end 102, the second end 104, and a third end 105. Thefirst end 102 and the second end 104 forms a diagonal line of theparallelogram. A line between the first end 102 and the third end 105 isparallel to the X direction. A line between the first end 102 and asecond end 104 is not parallel to the X direction. The second carbonnanotube film preform 22 connects to the carbon nanotubes of the thirdend 105 of the parallelogram of the first patterned carbon nanotubearray 10. In this way, each carbon nanotube film preform pulled fromeach patterned carbon nanotube array connects to the third end 105 ofthe parallelogram of previous patterned carbon nanotube array.

When the carbon nanotube film 100 is continually pulled out from thefirst end 102 of the first patterned carbon nanotube array 10 along theX direction, the number of the carbon nanotubes, in each cross sectionof the carbon nanotube film 100 perpendicular to the pulling directionand the width of the carbon nanotube film 100, remain substantiallyunchanged. It is understood that there may be some variations due tomanufacturing. The carbon nanotube film 100 has substantially uniformwidth and quantity of carbon nanotubes.

An embodiment of the method for making the carbon nanotube film 100 isshown where the carbon nanotube film 100 is pulled out from a secondcarbon nanotube structure preform 400.

Referring to FIG. 12, the second carbon nanotube structure preform 400includes N patterned carbon nanotube arrays and N−1 carbon nanotube filmpreforms. The N patterned carbon nanotube arrays are spaced from eachother and arranged along the X direction, N≧2. Each patterned carbonnanotube array includes the substrate 12 and a plurality of carbonnanotubes substantially parallel to each other and substantiallyperpendicular to the surface of the substrate 12. The plurality ofcarbon nanotubes forms the predetermined pattern. The predeterminedpattern includes the rectangle 106, the first triangle 108, and thesecond triangle 110 forming a parallelogram. The first triangle 108 andthe second triangle 110 are respectively located on two opposite sidesof the rectangle 106. The rectangle 106 includes a first side 1060 and asecond side 1062 opposite to the first side 1060. The first triangle 108and the rectangle 106 share the first side 1060, the second triangle 110and the rectangle 106 share the second side 1062. The first side 1060and the second side 1062 of the rectangle 106 are perpendicular to the Xdirection. The parallelogram includes the first end 102, the second end104, and the third end 105. The first end 102 and the second end 104form the diagonal line of the parallelogram, wherein an angle betweenthe diagonal line of the parallelogram and the X direction is about 45degrees. The line between the first end 102 and the third end 105 isparallel to the X direction.

Each carbon nanotube film preform is located between two adjacentpatterned carbon nanotube arrays and pulled out from a vertex angle ofthe first triangle 108 of N−1-th patterned carbon nanotube arrays. Eachcarbon nanotube film preform includes the first end point 222 and thesecond end point 224 opposite to the first end point 222. The first endpoint 222 is connected to the third end 105 of the parallelogram of theN-th patterned carbon nanotube array. The second end point 224 isconnected to the first end 102 of the rectangle 106 of N−1-th patternedcarbon nanotube arrays. The N−1 carbon nanotube film preforms aresuspended. The N−1 carbon nanotube film preforms include the pluralityof carbon nanotubes joined end to end by van der Waals attractive forceand extending along the X direction.

It is to be understood, preferring to FIG. 11, the parallelogramincludes two seventh sides parallel to each other, the third side 1080,and the sixth side 1102, wherein the third side 1080 and the sixth side1102 are parallel to each other. The third sides 1080 of adjacentpatterned carbon nanotube arrays are parallel to each other. The twoseventh sides are parallel to the X direction. The parallelogramincludes an acute angle defined as a and an obtuse angle defined as β.The acute angle of the parallelogram of each of the plurality ofpatterned carbon nanotube arrays is close to the obtuse angle of theparallelogram of the adjacent patterned carbon nanotube array. Eachcarbon nanotube film preform is located between two adjacent patternedcarbon nanotube arrays. Each carbon nanotube film preform is directlypulled out from a acute angle vertex 102 of the parallelogram of each ofthe plurality of patterned carbon nanotube arrays. The first end point222 of each carbon nanotube film preform is connected to an obtuse anglevertex 105 of the parallelogram of each of the plurality of patternedcarbon nanotube arrays. The second end point 224 of each carbon nanotubefilm preform is connected to the acute angle vertex 102 of theparallelogram of each of the plurality of patterned carbon nanotubearrays.

In summary, a plurality of patterned carbon nanotube arrays connected toeach other, implementing continuous production of the carbon nanotubefilm. Moreover, adjusting the shapes of the patterned carbon nanotubearrays can make the number of the carbon nanotubes of the carbonnanotube film remain unchanged, improving mechanical strength of thecarbon nanotube film. Furthermore, adjusting the shapes of the patternedcarbon nanotube arrays can also make the width of the carbon nanotubefilm remain unchanged.

The embodiments shown and described above are only examples. Even thoughnumerous characteristics and advantages of the present technology havebeen set forth in the foregoing description, together with details ofthe structure and function of the present disclosure, the disclosure isillustrative only, and changes may be made in the detail, including inmatters of shape, size and arrangement of the parts within theprinciples of the present disclosure up to, and including, the fullextent established by the broad general meaning of the terms used in theclaims.

Additionally, it is also to be understood that the above description andthe claims drawn to a method may include some indication in reference tocertain steps. However, the indication used is only to be viewed foridentification purposes and not as a suggestion as to an order for thesteps.

What is claimed is:
 1. A method for making carbon nanotube film,comprising the following steps: providing two carbon nanotube arraysspaced from each other and arranged along a X direction, wherein the twocarbon nanotube arrays comprises a plurality of carbon nanotubes;patterning the two carbon nanotube arrays to form two patterned carbonnanotube arrays successively defined as a first patterned carbonnanotube array and a second patterned carbon nanotube array; theplurality of carbon nanotubes of each of the two patterned carbonnanotube arrays form a parallelogram comprising two first sides parallelto each other and two second sides parallel to the X direction, the twofirst sides of adjacent patterned carbon nanotube arrays are parallel toeach other; the parallelogram comprises an acute angle and an obtuseangle, and the acute angle of the second patterned carbon nanotubearrays is adjacent to the obtuse angle of the first patterned carbonnanotube array; pulling out a first carbon nanotube film preform from afirst patterned carbon nanotube array acute angle vertex; pulling out asecond carbon nanotube film preform from a second patterned carbonnanotube array acute angle vertex and connecting the second carbonnanotube film preform to a first patterned carbon nanotube array obtuseangle vertex; and pulling out the first carbon nanotube film preformalong a pulling direction, and the pulling direction is parallel to theX direction.
 2. The method of claim 1, wherein the number of theplurality of carbon nanotubes in the carbon nanotube film and the widthof the carbon nanotube film remain substantially unchanged during thepulling out the first carbon nanotube film preform.
 3. The method ofclaim 1, wherein some carbon nanotubes of the acute angle vertex in thefirst patterned carbon nanotube array are drawn out, other carbonnanotubes are also drawn out end-to-end due to van der Waals attractiveforce.
 4. The method of claim 1, wherein an angle between a diagonalline of the parallelogram and the X direction is about 45 degrees. 5.The method of claim 1, wherein the first carbon nanotube film preformand the second carbon nanotube film preform comprise the plurality ofcarbon nanotubes joined end to end by van der Waals attractive force andextending along the X direction.
 6. The method of claim 1, furthercomprising treating the carbon nanotube film to form a carbon nanotubewire having uniform diameter.
 7. The method of claim 1, furthercomprising patterning the two carbon nanotube arrays by irradiating thetwo carbon nanotube arrays with a laser beam.
 8. The method of claim 1,wherein the pulling out the first carbon nanotube film preform isperformed at a uniform speed.
 9. The method of claim 1, wherein the twocarbon nanotube arrays are located in a same plane.
 10. A carbonnanotube structure preform, comprising: a plurality of patterned carbonnanotube arrays spaced from each other and arranged along a X direction,N≧2; each of the plurality of patterned carbon nanotube arrays comprisesa plurality of carbon nanotubes substantially parallel to each other;the plurality of carbon nanotubes form a parallelogram comprising twofirst sides parallel to each other and two second sides parallel to theX direction, the two first sides of adjacent patterned carbon nanotubearrays are parallel to each other; the parallelogram comprises an acuteangle and an obtuse angle, and the acute angle of the parallelogram isadjacent to the obtuse angle of adjacent parallelogram; and a pluralityof carbon nanotube film preforms located between two adjacent patternedcarbon nanotube arrays, each of the plurality of carbon nanotube filmpreforms directly pulled out from each of the plurality of patternedcarbon nanotube arrays comprises a first end point and a second endpoint opposite to the first end point; the first end point of the eachof the plurality of carbon nanotube film preforms is connected to anobtuse angle vertex in each of the plurality of patterned carbonnanotube arrays, and the second end point in the each of the pluralityof carbon nanotube film preforms is connected to an acute angle vertexin each of the plurality of patterned carbon nanotube arrays.
 11. Thecarbon nanotube structure preform of claim 10, wherein each of theplurality of patterned carbon nanotube arrays further comprises asubstrate, and the plurality of carbon nanotubes is substantiallyperpendicular to a surface of the substrate.
 12. The carbon nanotubestructure preform of claim 10, wherein the plurality of carbon nanotubefilm preforms is suspended.
 13. The carbon nanotube structure preform ofclaim 10, wherein an angle between a diagonal line of the parallelogramand the X direction is about 45 degrees.
 14. The carbon nanotubestructure preform of claim 10, wherein the plurality of carbon nanotubefilm preforms comprises the plurality of carbon nanotubes joined end toend by van der Waals attractive force and extending along the Xdirection.
 15. The carbon nanotube structure preform of claim 10,wherein the plurality of patterned carbon nanotube arrays has the samestructure and size.
 16. A method for making carbon nanotube film,comprising the following steps: providing a carbon nanotube structurepreform, comprising: a plurality of patterned carbon nanotube arraysspaced from each other and arranged along a X direction, N≧2; each ofthe plurality of patterned carbon nanotube arrays comprises a pluralityof carbon nanotubes substantially parallel to each other; the pluralityof carbon nanotubes form a parallelogram comprising two first sidesparallel to each other and two second sides parallel to the X direction,the two first sides of adjacent patterned carbon nanotube arrays areparallel to each other; the parallelogram comprises a parallelogramacute angle and a parallelogram obtuse angle, and the parallelogramacute angle in the parallelogram is adjacent to the parallelogram obtuseangle in adjacent parallelogram; and a plurality of carbon nanotube filmpreforms located between two adjacent patterned carbon nanotube arrays,each of the plurality of carbon nanotube film preforms directly pulledout from each of the plurality of patterned carbon nanotube arrayscomprises a first end point and a second end point opposite to the firstend point; the first end point of the each of the plurality of carbonnanotube film preforms is connected to an obtuse angle vertex in each ofthe plurality of patterned carbon nanotube arrays, and the second endpoint of the each of the plurality of carbon nanotube film preforms isconnected to an acute angle vertex in each of the plurality of patternedcarbon nanotube arrays; and pulling out a carbon nanotube film from thecarbon nanotube structure preform along a pulling direction, and thepulling direction is always parallel to the X direction.
 17. The methodof claim 16, wherein each of the plurality of patterned carbon nanotubearrays further comprises a substrate, and the plurality of carbonnanotubes is substantially perpendicular to a surface of the substrate.18. The method of claim 16, wherein the plurality of carbon nanotubefilm preforms comprises the plurality of carbon nanotubes joined end toend by van der Waals attractive force and extending along the Xdirection.
 19. The method of claim 16, wherein the plurality of carbonnanotube film preforms is suspended.
 20. The method of claim 16, whereinsome carbon nanotubes of the acute angle vertex are drawn out, othercarbon nanotubes are also drawn out end-to-end due to van der Waalsattractive force.